1. The Technical Field that the Invention Belongs to
The present invention relates to an estimation device using a radar to detect dangerous objects for a vehicle.
Especially the present invention relates to the estimation device for distinguishing various kinds of non-dangerous objects which are generally met in typical vehicle driving environment and the dangerous objects which are authenticity.
2. Prior Art
A lot of trials to discriminate the dangerous objects that can be trusted, were performed in a field of a vehicle radar system to measure a distance to the dangerous objects and a relative velocity thereof.
In a Japanese Patent Laid-open No. 6-282798 bulletin, a target search device is mentioned, the target search device comprising a target capture means to capture the target by searching periphery of a service body and to get a relative position of the target to the service body, a circular orbit estimation means to estimate a circular orbit of the service body in a turning motion of the service body, based on the relative position of the target which the target capture means got and the circular orbit of the service body (4) which the circular orbit estimation means estimated, and a control means to judge whether the target is located in the circular orbit and to distinguish the target located on a course of the service body.
In a Japanese Patent Laid-open No. 8-83400 bulletin, a method to distinguish dangerous objects for the vehicle from the objects which is not the dangerous objects in the vehicle radar system which can detect at least one object on the road near the vehicle driving in the first vehicle lane is mentioned, said method comprising the steps of a step to generate a radar beam having enough beam width to irradiate the object in the first vehicle lane and a second vehicle lane which is next thereto, and at least a part of the radar beam generated along a first axis which is generated in a right angle substantially, a step to receive a message of a reflex signal from the object irradiated, a step to estimate a velocity of the object irradiated about a vehicle velocity in a direction of the second axis (x) which is substantially parallel to the service direction of the vehicle based on reflection signal, a step to measure the velocity of the vehicle using at least one velocity sensor, a step to judge the irradiated object to be dangerous when a sum of measured the vehicle velocity and estimated the velocity which is parallel to the object is bigger than a predetermined threshold, and a step to judge the irradiated object not to be dangerous when a sum of measured the vehicle velocity and estimated the velocity which is parallel to the object is smaller than the predetermined threshold.
The Subject that Invention is Going to Solve
A sensing requirement for a system should be thinking about as that a distance with a preceding vehicle(including stopping vehicle and an object, herein after called as a target) is controlled to be a desired value (ACC: Adaptive Cruise Control) by detecting the lead car in forward of host vehicle lane, or a collide warn is occurred when coming too much close to the preceding vehicle or the target.
For example, following three phases may be considered.
The first step: A detectivity ability, that is, may the forward target (the vehicles and road side object) be recognized?
i) A distance to the target (max especially), relative velocity and detectivity power of angle.
ii) An accuracy of the vehicle lane judgment of the host vehicle lane/others vehicle lane.
The second step: Discrimination ability, that is, may the forward target be recognized?
Especially, is the forward stationary object in forward of the host vehicle discriminated? (For example, the road side object such as a stationary vehicle, a corner pole and road signs, and an object on the road such as an overhead bridge can be distinguished?)
The third step: Intention decision, that is, which direction is the driver going to go to?
Is the forward obstacle included in a driving path in the future based on the driver intention? (there is no need to occur the warning when not included.)
Referring to the above, an object of the present invention is to provide a vehicle lane position estimation device of the preceding vehicle or the target by improving the vehicle lane decision accuracy of the host vehicle lane/others vehicle lane and by detecting the preceding vehicle in forward of the host vehicle lane or the target, so that the distance with the preceding vehicle is controlled to be a desired value or a collision warning to prevent the collision with the target is generated in accurate.
Further, another object of the present invention is to provide a vehicle lane position estimation device of the forward stationary object which may recognize in accurate whether the stationary object is a dangerous objects on the host vehicle lane or not or whether it is on the host vehicle lane or not.
Further, another object of the present invention is to distinguish the stopping preceding vehicle and the stationary object such as a road sign on the road side or an overhead bridge, and to warn or control (decelerate) the stopping vehicles which is in forward of the host vehicle.
A Means to Solve the Subject
According to the present invention, algorithm for estimating the host vehicle lane to be accurate in a curved road and for estimating an accurate correction when a position correction is necessary, is provided on the basis of a movement of the preceding vehicle which the radar caught and other sensor information, various data from the vehicles side are received, vehicle lane position estimation of the preceding vehicle is performed with a sensing information got by a millimeter wave radar, and a one body type millimeter wave radar system is built in a communications network function that can transmit an warning or a control command information to the vehicle side and decision/control function, is provided.
In such the vehicle lane position estimation device as above, the present invention further comprising a means for judging whether a curve of said road is a transition curve section where a curvature radius thereof changes every moment sometimes, or a maximum curve section where said curvature radius does not changes, and a means for correcting a curvature radius Rf of said host vehicle used for correcting said curvature radius Rf of said preceding vehicle to be smaller than a predetermined value when a transition curve is in an introduction part of the curve, and for correcting said curvature radius Rs to be larger than said predetermined value when said transition curve is in an rear part of the curve.
In such the vehicle lane position estimation device as above, a vehicle lane boundary position is obtained by estimating a vehicle lane position of plural preceding vehicle, the host vehicle is judged to be right or left of the vehicle lane boundary, and a vehicle lane judgment position of said host vehicle is offset towards right or left.
In such the vehicle lane position estimation device as above, the present invention further comprising a millimeter wave radar and a gyro sensor are used as said means for measuring.
In such the vehicle lane position estimation device as above, the present invention further comprising a means obtaining a distance of the vehicles from said preceding vehicle, and a means for warning when said distance becomes a predetermined distance.
The present invention relates to a vehicle lane position estimation device for estimating a position of a vehicle lane of a stationary object (a forward stationary object) to be located before an host vehicle, comprising a means for measuring a distance between said host vehicle and said preceding vehicle or an oncoming vehicle, a direction angle from said host vehicle, an angular velocity and a velocity of said host vehicle, a one vehicle lane sensing means for obtaining a vehicle lane of a road, a means for calculating a lateral displacement between said host vehicle and said preceding vehicle or said oncoming vehicle, a longitudinal displacement therebetween and a curvature radius of said host vehicle, a means for capturing a forward stationary object, a means for obtaining a movement of said preceding vehicle or a position of said oncoming vehicle, a means for estimating a vehicle lane position of said forward stationary object from a movement relationship of said preceding vehicle obtained and said forward stationary object captured or a position relationship with said oncoming vehicle, and a means for warning when said forward stationary object is in a vehicle lane of said host vehicle.
In such the vehicle lane position estimation device as above, the present invention further comprising a means for recognizing whether said forward stationary object is an object on the road such as an overhead bridge.